Not with VBScript or VBA.
However you can get a 3rd party solution called AutoIt. It is free at http://www.hiddensoft.com/autoit3/index.php
To disable mouse and keyboard input:
Set oAutoIt = CreateObject("AutoItX.Control")
Input will be automatically enabled when the script closes if you don't issue an off command.
You can also simulate input (automated keyboard and mouse entries.)
You may need to reference a script to get this installed on the users' machines. See AutoItX which enhances VBScript (VBA, really.)